Hezonja was promoted to the club level in his native Croatia when he was 12 years old, and at the age of 13, he stayed for two seasons with Dubrovnik.

[citation needed] In July 2012, Hezonja signed a three-year contract with Spanish club Barcelona, at the age of 17.

For the 2012–13 season, he was loaned to the reserve team of the club, Barcelona B of the LEB Oro, the Spanish second-tier level division.

[citation needed] On 23 April 2015, Hezonja declared himself eligible for the 2015 NBA draft, as an international "early-entrant", just days after Barcelona's elimination in the EuroLeague.

[4] He had been identified as a potential lottery pick early in his career, and surprised some by opting not to declare for the draft in 2014, his first year of eligibility.

[10] He made his debut for the Magic in the team's season-opening loss to the Washington Wizards on 28 October 2015, recording 11 points in 25 minutes off the bench.

[12] On 28 February 2016, he made his first career NBA start and dunked four seconds into the game, finishing with 13 points on 5-of-9 shooting in 27 minutes of action in a 130–116 win over the Philadelphia 76ers.

Hezonja finished the season making 79 appearances with the averages of 6.1 points, 2.2 rebounds and 1.4 assists on 43.3 field goal percentage.

[21] On 17 December, Hezonja scored a then-career-high 28 points and had six rebounds and two assists, while shooting 8 from 12 from the three-point line, in a 114–110 loss to the Detroit Pistons.

[25] On 5 April, he recorded his first career triple-double, logging 16 points, 16 rebounds and eleven assists in a 96–120 loss to the Houston Rockets.

[26] Two days later, Hezonja scored a career-high 30 points, alongside six rebounds, five assists and two steals, in a 113–110 win over the Washington Wizards.

Enes Kanter Freedom, Hezonja's Turkish teammate on the Portland Trail Blazers, allegedly played a vital part in his transfer to the Greek powerhouse, having also expressed his sympathies towards both Panathinaikos and the country of Greece in the past.

[36] Hezonja was named Most Valuable Player of the 2011 FIBA Europe Under-16 Championship, after leading his team with a double-double in the final, 21 points, 10 rebounds and three steals.

[citation needed] Hezonja was part of the senior Croatian national team that participated at the 2014 FIBA Basketball World Cup.